When one talks about security, it's really hard for people to follow what she really means; the context has always been qualitative, but not quantitative.
I found the idea "Vertical/Horizontal Attack Profile" interesting, which may help measure security when people argues different container solutions or even VMs.
https://blog.hansenpartnership.com/measuring-the-horizontal-...
Do you think LXD gets closer to Zones in terms of security?
>Actually K8s [...] are slowly adding all the secure options by default [...] (user namespacing being the most notable).
K8's RBAC is nice, and in particular auth-delegator really helps with odd duck integration for the enterprise. But k8s is reliant on OS features to make user namespaces happen and Redhat customers are still waiting for Redhat to backport a newer version of shadow-utils [1] [2] to RHEL 7 so that user namespacing works there.
Given enterprise certification and release cycles "Wait for RHEL 8" isn't really a good answer for those kind of customers. I'm not disagreeing with you, just saying some features of kubernetes aren't available everywhere. Personally I'd really like to see user namespaces come to RHEL 7 as it helps with removing or mitigating privileged access.
[1] https://bugzilla.redhat.com/show_bug.cgi?id=1498628 [2] https://access.redhat.com/solutions/3657531
The main difference then is usability, which is almost always the biggest security flaw in any piece of software (that the security isn’t “on” by default or has a prohibitive learning curve for the user).